The spinal column is a highly complex structure which houses and protects critical elements of the nervous system. In spite of these complexities, the spinal column is a highly flexible structure, capable of a high degree of curvature and twist through a wide range motion. Genetic or developmental irregularities, trauma, chronic stress, tumors, and disease, however, can result in spinal pathologies which either limit this range of motion, or threaten the critical elements of the nervous system housed within the spinal column.
In various orthopedic surgical procedures, it is necessary to stabilize portions of a spinal column relative to one another. This need is typically a result of disease, damage or congenital deformation. In one method of treatment for intervertebral disk degeneration, the normal gap between adjacent vertebral bodies is surgically re-established and maintained with a rigid spacer inserted between the bodies. The rigid spacer is filled with bone graft material to facilitate bony fusion of the two vertebral bodies. A successful fusion stabilizes the spine, reduces pressure on the spinal cord and nerve roots, and reduces or eliminates back pain.
While known devices for spinal fusion have proven to be effective in various applications, there remains a need for spinal implants that do not require large incisions for implantation, that can relieve localized stress on adjacent vertebral end plates, and that can prevent migration and retropulsion within the spinal column.